New Zealand trainer and chef d'equipe John Cottle was one of the original people behind the clash.
“We just don't have enough team competitions in New Zealand and it brings with it quite a different way of riding,” the two-time Olympian said.
“It is added pressure for these young riders when they are jumping for their team.”
The riders will only be allowed to jump their horses just before they head into the arena.
“The challenge is for them to get used to a horse — not training it but rather adapting to and reading that horse.”
Cottle says the Kiwi team are a strong bunch.
“We have some very talented riders in there.”
While the Australians are unknown, he has no doubt they will bring their A-game.
The chance for the riders from both teams to network and create new friendships enhances the clash.
The test will run over three days, with points awarded for double clears and wins.
It is part of three big days of competition at the popular annual championships.
John Vallance is the course designer for Ring 1, with Edward Bullock in Ring 2.
Australian Vallance, an FEI (Fédération Equestre Internationale) Level 4 four designer, has been part of three Olympic Games among other top events.
There is a full schedule of showjumping and show hunter classes, including series classes which have attracted top horses and riders.